In
the pantheon of bizarre anti-intellectual, anti-science, religiously inspired
ideas even geocentrism (the idea that the earth is the unmoving centre of the
universe) still exists. All forms of geocentrism are rejected by all serious scientists;
its modern proponents are scientifically ignorant, religiously motivated cranks
such as the self-appointed Roman Catholic apologist, Robert Sungenis (1). (Robert
Sungenis is also a Young Earth Creationist with all the science-denying obfuscating
counter-Enlightenment baggage that goes along with that discredited notion).
Sungenis's geocentric
nonsense is, I hasten to add, peculiarly his, and is not officially sanctioned
by any institutional body of the Catholic Church. Indeed I get the impression
that Sungenis is something of a embarrassment to the Church. Here is a summary of the arguments that
demonstrate that modern geocentrism (2) is not a tenable hypothesis for a reasonable person
with a moderate knowledge of modern physics. Please note that I am not seeking
to prove the truth of heliocentrism or any-other-centrism, but merely to show why geocentrism is not tenable.

The whole argument can be summarised in one sentence, so if you can't be bothered
to read the whole article, just read the next sentence:

In Newtonian mechanics, geocentrism cannot be true for many
physical reasons; in General Relativity the centre of the universe has no
meaning, so to claim that the earth is the centre of the universe is
meaningless; in neither system can the earth be said to be the unmoving
centre of the universe

I’ll also argue that the
promotion of geocentrism is unnecessary for salvation, is contrary to reason,
and represents a major source of scandal, calling ridicule down on the Church
and the Faithful

In Newtonian mechanics, geocentrism cannot be true for many physical reasons

Newtonian mechanics works within Euclidean geometry, which, for our
purposes, we can summarise as a three dimensional spatial geometry based on an
absolute space. Euclidean space is absolute and independent of matter or
energy, which exist within Euclidean space without, in any way, affecting it.
In addition, Newtonian mechanics relies on an additional dimension of absolute
time.

Note that the concept of the equivalence of reference frames exists in
Newtonian mechanics. It is a mistake to think that the idea that reference
frames are equivalent is a new finding of Special or General Relativity.
Indeed, the concept of relativity and the equivalence of reference frames was
first understood by the great scientist, Galileo, whose name is given to the
mathematical expressions used to transform between reference frames in
Euclidean geometry - these expressions are called Galilean transformations
after him.

Galilean relativity states that relative
motions of systems of bodies are the same no matter what inertial reference
frame they are in, where an inertial reference frame is one in which the motion
of a body not subject to forces is in a straight line and uniform and where the
acceleration of bodies is proportional to applied forces. In Newtonian
mechanics inertial reference frames move uniformly and rectilinearly with
respect to one another.

Newton used this property of Galilean
relativity in his calculations of planetary motion. It follows from the
definitions of inertial frames and their equivalence that the centre of mass of
an isolated system of bodies is at rest in an inertial frame. Newton reasonably
approximated the solar system as an isolated system of bodies (this is not
strictly true, but the forces and influence of the rest of the universe on
relative motions within the solar system are vanishingly small on the scale of
years). Within this reference frame, he then calculated the accelerations that
would result from the gravitational forces between the bodies. Newton rejected
the notion of geocentrism and heliocentrism (neither of which were ever to make
an appearance in physics again); instead it is the centre of mass of the system
of bodies (in this case the solar system), that is at rest with respect to the
reference frame - all the other bodies (including the sun) experience
accelerations and are not therefore at rest in the inertial frame. The sun, of
course, is vastly more massive than every other body in the solar system, and
so its centre is nearly at the centre of mass of the solar system and nearly
stationary with respect to it, but not quite. So heliocentrism, within the
solar system, can be seen as a close approximation to the Newtonian case. All
of this is true whether we observe this from an inertial frame at rest with
respect to the solar system or the fixed stars, as we can transform between them
using the Galilean transformation.

It
is unreasonable to hold that the earth is the unmoving centre of the universe
according to Newtonian physics, in which there is an absolute space. The
arguments against geocentrism in a Newtonian universe are overwhelming and have
been rehearsed many times. I do not intend to go into them in detail, but I
list some of them below:

Satellites are launched to the east because the earth's rotation
boosts the velocity of the satellite and helps it to achieve orbital velocity
- the earth is used as a sling shot

Satellite launch sites are as close to the equator as nationally
possible for the same reason as 1.

Points at rest or in uniform motion in inertial frames of reference
(which in Galilean relativity are frames of reference in which a point not
under the influence of applied force continues in rectilinear and uniform
motion), have no unresolved forces

The earth has obvious unresolved forces
(Items 3 and 4 have relevance in Riemannian geometry too)

Foucault's pendulum demonstrates the existence of unresolved forces
at the surface of the earth

Weather systems always rotate counter clockwise in the northern
hemisphere and vice versa in the southern hemisphere owing to the coriolis
force of rotation

Oblate earth - the earth has a greater girth at the equator than
across the poles owing to the centrifugal force of the earth's diurnal
rotation

Parallax in the star fields as a consequence of earth's rotation
round the centre of gravity of the solar system

Red shift in the star field as a result of ditto

A star field with a radius of 14 billion light years and a mass
3x10^27 times that of the earth rotating around the earth once a day and
wobbling with a amplitude of 186 million miles at an angle of 23.5 degrees
annually is an untenable dynamical system in Newtonian mechanics

Systematic forces which explain the dynamics of retrograde
planetary motion are not available in a Newtonian gravitational system

Interestingly, there is a
serious sense in Newtonian mechanics that refutes the idea of not just the
earth, but any body being the unmoving centre of the universe. Even if
we accept, for the sake of argument, that the universe is spatially finite, and
we accept that there is a point in absolute space that corresponds to its
centre of mass, no object with finite mass and finite spatial extent can be permanently at rest with
respect to that point, because all objects with finite mass and spatial extent necessarily
experience accelerations caused by the gravitational forces resulting from the
presence of other bodies of finite mass in the universe, accretions of matter
and other Newtonian interactions, in addition to tidal gravitational forces
(ie forces resulting from gravitational gradients within the finite spatial
extent of the body) and they therefore
cannot be permanently at rest in any given Newtonian inertial frame.

Geocentrism is meaningless in General
Relativity

Geocentrism, indeed any-centrism, is
meaningless in the formulation of GR that accurately describes the universe
structure. So let's see what that is.

First of all, solutions to Maxwell's
electromagnetic equations yielded an expression which showed that the
speed of propagation of electromagnetic energy (light) is constant irrespective of the frame
in which you measure it. So now we have a phenomenon that disobeys the
principle of Galilean relativity. The solution to this conundrum is Einstein's
special relativity. The inconsistencies between constant c, the speed of light
in vacuo and Galilean
relativity are resolved by giving up the idea that length and time are
independent of reference frame. The Galilean transformation is replaced by the
Lorentzian transformation and Newtonian spacetime by Minkowski spacetime. We
have to give up the concept of simultaneity - events that appear simultaneous
in one reference frame do not appear simultaneous in another, so we also lose
the concept of absolute time.

Einstein then developed his
insight that the force of gravitational attraction is indistinguishable and no
different in principle from the force of acceleration.

The Einstein equivalence principle states that
in a local inertial reference frame the outcome of any non-gravitational
experiment is independent of the velocity of the frame or its position in
spacetime and that the laws of nature are those of special relativity. This
does NOT mean that rotation is the same as being static nor does it deny the
special status of inertial reference frames; in fact, EEP holds only in
inertial reference frames

The consequence of this is that in General
Relativity (GR), spacetime is not flat as it is in Newtonian mechanics or Special
Relativity, but is curved. Moreover, the curvature is determined by the
presence of mass. We now have to work in non-Euclidean geometry, with no
absolute flat co-ordinate system. In order to calculate the dynamic behaviour
of masses we have the complex problem that the presence of the mass curves
spacetime in such a way as to create what we observe as the gravitational force
(although in GR we shouldn't think of gravity as a force) between them, but
also influences the geometry of space and time in their locality. We have to
work in Riemannian geometry using tensor analysis, the details of which are way
beyond the scope of this article.

The Einstein field equation is the generalised
formulation of gravitational physics and one of the reasons that it is
expressed in terms of tensors is that doing so allows a co-ordinate free
description. It is important that no co-ordinate system is deemed to have
precedence, as it is possible, in any such preferred system, to re-introduce
the discarded notion of gravitational force. So GR is formalised in a
co-ordinate free manner.

From a cosmological perspective, there have
been various attempted solutions of the Einstein field equation, the most
successful of which, the Friedmann-Robertson-Walker solution closely reflects
the observed universe. In the FRW metric, the universe is homogeneous and
isotropic, that is, from any point it looks the same in all directions and its
properties at all points are the same.

In a homogeneous universe the curvature of
space time is invariant with position and determined by the energy density of
the universe. Locally however, spacetime is curved by the presence of
massive objects.

Now what about the proposition that the earth
is the unmoving centre of the universe? Well, GR states that the effect of a
force resisting gravity and the effect of a force accelerating a reference
frame are identical and indistinguishable. In GR, spacetime geometry is determined
by the distribution of matter/energy in the universe (there is no absolute
space) and the spacetime geometry influences the flow of matter/energy. It is
therefore utterly meaningless to talk about a spatial centre for the universe
because in GR, space has no absolute meaning.

Mach’s principle states that inertia is not
absolute but depends on matter in the universe. Matter/energy there determines
inertia here. There is no such thing as absolute rotation in the universe
independent of the distribution of matter, and no absolute space. The closest
we can get to a definition of absolute rotation is rotation with respect to the
average distribution of matter in the universe: the distant stars; or rotation
with respect to a local inertial frame (which is, in fact, very closely aligned
to the star field, although this alignment can be slightly perturbed by the
influence of large nearby masses)

General covariance applies
in all inertial frames of reference. It is extremely misleading, and a
characteristic error of geocentrists to claim that in GR, all reference frames
are equivalent. They are not. Let's do a thought experiment. Let’s imagine we
are in a spacecraft, with blacked out windows, that is rotating so that the
centrifugal force creates an artificial gravity – we are pinned against the
walls of the craft by this force. We then employ the steering motors of the
spacecraft to manoeuvre the craft so that all forces that we can measure within
the craft disappear. We open the window blinds and what do we see? The craft is
not rotating with respect to the stars. The craft is now at rest within what we
call a local inertial frame of reference, one in which there are no measurable
residual forces due to linear accelerations. According to Mach, matter/energy there
determines inertia here, so the inertial frame aligns closely with the
star field (with local perturbations due to large nearby rotating masses - a
phenomenon known as frame dragging).

In GR, an inertial frame is defined as a frame
in free-fall in which an object at rest experiences no forces. The equivalence
principle applies only in inertial frames. The surface of the earth is
absolutely not an inertial frame in GR, because if you are standing on the
surface of the earth you experience a force due to the local curvature of
spacetime (gravity) as well as coriolis and centrifugal forces. Such forces do
not appear in an inertial frame.

Now we have seen that talking about a centre of
the universe in GR (or at least as far as the Friedmann- Robertson-Walker
metric solution to the Einstein field equation goes) is meaningless, but is it
meaningless to talk about absolute rotation? Well when astronomers and
cosmologists talk about rotation in the universe they do so with respect to
local inertial frames (which we have seen are very closely aligned to the
distant stars), or with respect to the star field itself. So in GR, the formal
conclusion is that it is meaningless to posit absolute rotation independent of
matter in the universe, but that inertial frames are special (in that they
uniquely represent conditions with no detectable residual forces), they align
with the star field according to Mach’s principle, and if absolute rotation
means anything at all, it means being in a non-inertial reference frame rotating
with respect to the stars; in such a frame forces are detectable. The
Earth’s surface is just such a non-inertial frame: by this definition it
rotates. (3), (4), (5)

What about translation?
To the extent that we claim that an object is moving or is stationary, we need
to define that movement with reference to something. Although in relativity,
preferred inertial frames are rejected, the Cosmic Microwave Background
(the afterglow of the Big Bang) is taken as a special reference, and
is interpreted as the rest frame of the universe. Measurements of the dipole
of the Cosmic Microwave Background power spectrum show that the solar system
is moving with respect to the CMB at a velocity of 368 km/s and the galaxy and
Local Group of galaxies at a velocity of 600km/s, (6), (7).

To summarise
this section, in General Relativity the concept of the centre of the universe
has no meaning. Furthermore, to the extent that any reference frames are special,
inertial frames and the rest frame of the CMB have that distinction. The earth's
surface is not at rest in an inertial frame and the earth has a significant
velocity with respect to the CMB and so there is no sense in which we can say
that earth is stationary in the centre of the universe.

Apples are not Frogs

Geocentrists also confuse kinematic
transformations with dynamic transformations. Just because a kinematic
transformation is possible does not mean that the physics cannot distinguish
between the two reference frames. Here's a simple example. A flea leaps off the
surface of the earth. Now there is nothing wrong with describing that event
kinematically in a reference frame stationary with respect to the flea. In such
a reference frame the earth accelerates away from the flea rapidly to a maximum
velocity at the point where the flea loses contact with the earth. Thereafter,
the earth continues to move away from the flea but more and more slowly until
the earth stops and begins to accelerate back towards the flea. The earth
eventually hits the flea at about the same speed that they originally parted.
The earth then slows down and stops. (The event can be described from an earth
frame of reference simply by swapping the words flea and earth)

From a dynamic point of view the reference
frames are not equivalent. A point in the flea's reference frame will
experience forces associated with the flea's rapid acceleration and
deceleration. A point in the earth's reference frame will experience almost
zero force as the acceleration of the earth's frame due to the flea's antics is
very very very tiny. Dynamically it is not correct to say that the earth leapt
off the flea. (Strictly speaking, the reference frame that experiences zero
acceleration and zero force as a result of this experiment is one in which the
centre of gravity of the flea and the earth is at rest.)

Similarly, it is not dynamically correct to
say, as you must if you hold that the earth is the unmoving centre of the
universe in an absolute space, that the impact of a large meteorite on the
earth causes an absolute acceleration of the entire universe.

A Sungenis specific error

A particular Sungenis nonsensical
idea is his reference to the
‘gyroscopic rotation of the universe stabilising the earth at its centre of
mass’. First of all, this confuses solid body dynamics with many-body
kinematics. Secondly if he really believed in the equivalence of the rotating
and static star field reference systems he would acknowledge that the
‘stabilising forces’ would have to exist in both co-ordinate systems – but
where in the reference frame at rest with respect to the distant stars are we
to find forces that prevent the earth from wandering off through the universe
due to the influence of locally acting forces such as gravitational attraction
to large masses. Indeed, as we have seen, the measurement of the CMB anisotropy indicates a
relative motion between the solar system and the primordial radiation of the
early universe of 368 km/sec (Incidentally, the CMB also aligns with, ie does
not rotate with respect to the star field and local inertial frames, so we can
say that the star field frame and the local compass of inertia is at rest with
respect to the spacetime manifold of the primordial universe as described by
the FRW model)

Geocentrism harms the church and the faith

Geocentrism is either wrong or meaningless depending
on whether you are working in Newtonian mechanics or GR. A belief in
geocentrism doesn't harm one's ability to get to heaven any more than a belief
in young earth creationism, a literal belief in Noah's flood or a belief in
Santa
Claus or pink unicorns (except to the extent that we suppress our reason, we are
suppressing one of the important faculties that distinguishes us from other
animals).

But neither is holding to the plain error of
geocentrism any help to the faithful. Frankly, most people don't care. The
majority of people who come across Sungenis's bunkum will see it as that. But
since Sungenis represents himself as a master apologist for the Catholic Church, then it's the
Catholic Church that gets smeared with the buffoonery. It's certain that Sungenis causes
scandal and damages the Church’s reputation amongst the faithful and unbelievers
because of his insistence on this scientifically wrong and theologically
unimportant point. It is appalling science, poor apologetics and abysmal
evangelism.

He can't hope to convince scientists, because the geocentric
idea
is scientific candy-floss, uninteresting and meaningless in modern cosmology,
promoted only by acolytes who themselves lack any fundamental scientific understanding.

Summary

To summarise, in order for the ‘centre of the
universe’ to have meaning, we need an absolute space. In such a space,
Newtonian mechanics (plus special relativity) applies, and there are many
compelling reasons in that system which show that the earth cannot be the
unmoving centre. In order to refute these reasons, Sungenis calls on General Relativity, but in
General Relativity talk of a centre is meaningless (Sungenis also vehemently denies the
propositions of General Relativity so
logically he shouldn’t use it; he wants to have his cake and eat it). In an absolute space
(Euclidean-Newtonian) model the earth cannot be
at the centre and in a GR model there is no centre. Sungenis is caught in a
fundamental logical inconsistency.